﻿class Solution
	 {
 public:
	 bool isInterleave(string s1, string s2, string s3)
		 {
		
			 int m = s1.size(), n = s2.size();
		 if (m + n != s3.size()) return false;
		 s1 = " " + s1, s2 = " " + s2, s3 = " " + s3;
		
			 vector<vector<bool>> dp(m + 1, vector<bool>(n + 1));
		 dp[0][0] = true;
		 for (int j = 1; j <= n; j++) // 初始化第⼀⾏
			 if (s2[j] == s3[j]) dp[0][j] = true;
		 else break;
		 for (int i = 1; i <= m; i++) // 初始化第⼀列
			 if (s1[i] == s3[i]) dp[i][0] = true;
	else break;
		
			 for (int i = 1; i <= m; i++)
			 for (int j = 1; j <= n; j++)
			 dp[i][j] = (s1[i] == s3[i + j] && dp[i - 1][j])
			 || (s2[j] == s3[i + j] && dp[i][j - 1]);
		return dp[m][n];
		 }
	 };